A terrific find! Either solution would make a good problem on its own. In the first solution 1…g1=Q puts a guard on e3, preventing 2.Ke3??. Then 4…e1=B must be delayed until after 4.Kf2. It is also neat how the bQ guards h5, so the check must be on h4. In the second solution the bR must unguard g1 as quickly as possible, which forces the black move order. Then Black must guard g1, but 4…e1=B? 5.Kh1 Bf2 6.Rg3+ Bxg3!